Over the past ten years, there has been a need to integrate technologies for exogenous stimulation of the brain with endogenous activation of the brain. The rapid growth of different technologies to affect cortical excitability has led to new directions in rehabilitation science. However, this has also led to a number of new challenges. Primary among these challenges is that despite the increase in availability of non-invasive stimulation techniques, we still do not understand how the application of these technologies affects patterns of cortical activity at baseline prior to stimulation. The net result of this lack of information about baseline state is that we may be applying incorrect stimulation parameters in our attempts to facilitate rehabilitation across numerous cognitive and motor domains. For many years, we have used electroencephalography (EEG) to measure cortical oscillations (frequencies of electrical stimulation) to attempt to understand how regional areas of the brain function in differing state. These states may be during specific task activity, at rest, or in cases of frank pathology. Changes in cortical oscillations have been associated with decreased motor performance as a function of aging and after frank insult to the cortex, as in stroke. For example, older adults who show in increase in a particular frequency (beta) between brain hemispheres during finger movements typically have difficulty performing these tasks, yet we have yet to determine why this is the case. In language, older adults who show increased synchronization of a specific EEG frequency in frontal regions associated with the production of ordered speech tend to have impaired naming and word recall performance. Over the past decade, the implementation of non-invasive brain stimulation has become commonplace in attempting to remediate such difficulties, particularly in individuals with frank pathology. However, we have had a fairly disappointing success rate when applying one-size-fits-all protocols of cortical stimulation in associated clinical trials. We believe a major reason for the negative trial outcomes in studies using non-invasive brain stimulation is that practitioners are not appropriately accounting for cortical activity prior to administration of the selected stimulation paradigm. Combining EEG prior to the administration of tDCS affords us the capability to personalize treatments in the lab and then to the clinic to best help our Veterans based on their specific cortical profiles of activity. Critically, this can be done across different pathologies ranging from neurological insult, aging-related declines, visual impairment and psychiatric populations. The current application represents interest in the use of the StarStim EEG/tDCS system by 5 VA-affiliated researchers as Major Users. The Major Group includes: Keith McGregor, PhD (PI), Steve Wolf, PT, PhD, Bruce Crosson, PhD, and Amy Rodriguez, PhD, CCC-SLP. The Minor group includes: Joe Nocera, PhD, Erica Duncan, MD, Machelle Pardue, PhD. These users represent a strong core of researchers with interests in using the StarStim to improve healthcare delivery to Veteran's by improving our understanding of cortical networks.